NORMANDY, MO (CBS Local) – A Missouri school security officer has been arrested after allegedly using a stun gun on a 14-year-old student.

According to reports, the head of school security at Normandy Middle School confronted a half-day student who was preparing to leave the building at around 11 a.m. Central time on April 20. School surveillance videos then show the security guard using his weapon on the teen.

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“The video shows the security person pin the student against the wall and jab him with a stun gun,” Normandy Police Chief Frank Mininni said, via the St. Louis Post-Dispatch. “From the pictures of the injuries I’ve seen, he had some red welts.”

A school resource officer, Ralph Ruffin, was the first person on the scene and had the student taken to a local hospital for treatment. The officer, who also works for the Normandy Police Department, then arrested the civilian guard for using a taser on a child – which is against the department’s policy. The unidentified guard was not charged with a crime. He was, however, placed on leave from his job at the school.

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The St. Louis County Prosecuting Attorney’s office is now seeking assault charges against the head of school security, according to KMOV. School district spokeswoman Sharifah Sims-Williams says 15 security guards were hired to provide an “extra layer of security” and prevent fights between students. Sims-Williams added that the district is cooperating with the ongoing police investigation.